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Photographing Pots

Increasingly exhibitions are asking for submission by photograph in the form of a slide or electronic image. While this saves a lot in cartage if your pots are rejected it puts a premium on good quality pictures. There is also an increasing demand for images for personal web pages like those on nzpotters.com  If you follow a few simple principles you can produce good pictures yourself without the need to hire a professional or buy floodlights.

If however you are wanting reproduction of a professional standard for professional purposes, e.g. large scale and exact colour reproduction for glossy print media then you need help from a professional photographer with professional equipment.

These are some simple instructions for other simple people like me.

  1. Work outdoors or in well-lit rooms away from direct sunlight. Ideal is abright cloudy day or a sunny day in a shaded area. The aim is to avoid shadows in your picture.

  2. Don’t use natural backgrounds. You want to show the pot - not the house, the path, the flowerbed, the grass, the barbecue, the cat, your spouse or your children.  They may look lovely but your pot doesn’t need them right now. Even if you designed it for garden use, it is the pot which needs to be seen, not your garden.

  3. Put your pot on  large neutral coloured matt card, or cloth without folds, which you can curve up behind the it.  Bring the pot as far forward from the backdrop as you can to further reduce shadowing. You can buy large sheets of card at low cost from drawing material suppliers. For really huge pieces you can use cloth but take care to drape them without folds or creases.

  4. Don’t use flash – it will produce highlights on the pot and shadows behind it.  If the light is too dim for a hand held shot use a tripod or wait for a brighter day.

  5. Take time deciding whether to take the picture straight on or a little above or below. If you are still not sure, take one of each and choose later.

Digital cameras are ideal for web images. You are not looking for a picture to blow up for a billboard so even a modest digital will produce excellent  images which fill a computer screen. When preparing images to send electronically, aim for files around  300k. If you are not sure if there is sufficient resolution, blow them up to fill your screen and check for quality.
And if you are using a digital you can afford to experiment with your techniques at no cost at all.

Jim Pollard
17-11-2014

Ideas for fixing kilns

One of the struggles with brick kilns used for salt or soda firing is coping with the expanding brickwork. Essentially each brick will expand and contract, by as much as 1mm along the longest side during the cycle of heating and cooling. When the brick expands it exerts force on all the surrounding bricks, this can push out the walls of the kiln and is the force responsible for pushing up the arch of the kiln and putting pressure on the tie rods. Then when cooling the brick contracts towards the centre of its mass, leaving a small gap between it and its neighbours. If this gap is filled, or loose material like wadding fills the gap then next time the kiln is heated the expansion will push the bricks further apart. This ratcheting action is the reason brick kilns slowly expand, or if contained by steel work will bow their walls out. Keeping the  gaps clear of material and tapping the worst gaps closed is the best option, but this is difficult in a salt or soda kiln as the glazed bricks essentially get stuck apart during the cooling as the glaze hardens and prevents the bricks from moving. So the only option is to fill the worst cracks.

The materials used depend on how much salt or soda the area receives, so in the high wear areas mixtures containing calcined alumina and china clay are common, in low risk areas then fireclay and silica sand or grog are fine. Adding 10% talc can help slightly flux the mixtures and prevent them crumbling out of the cracks. The clay content is never above 50% and often lower to prevent shrinkage cracks of the mixture. I’ve had good success with a cup of silica sand and a cup of china clay with 10% talc, made up to a soft putty and worked into the wall above the throat of my kiln, which cops all the soda being sprayed in. It’s never worth trying to patch a brick arch as they move so much during a firing that crumbs will inevitably fall onto your best piece.

Another tip to prevent the soda vapour penetrating past the hot face bricks is to make sure the outside of the kiln is well sealed with no cracks leading from the inside to the outside, then the vapour will only be pulled towards the chimney.

In areas with the greatest wear like throats and bagwalls then liberal coatings of kiln wash (1 part china clay, 2 parts calcined alumina) each firing help to prevent brick decay. Even so a new surface needs to be applied every so often on some crucial bricks that may be used to place pots on. For these situations I use either a kiln wash, or the 50/50 mixture mentioned above and thicken it with wall paper paste that is made up to a paste. This makes for easy application, a thick layer that won’t crack and if it needs to be removed will chip off easily. It will also fill holes and will level up the bricks again.

Duncan Shearer
22-2-2014

 

 

If you have a tip please email the text and images to lawrenceewing8@gmail.com

New Zealand Potters (Inc.)


Registered as an incorporated society in 1965 by an enthusiastic group of potters in Wellington, New Zealand, NZ Potters (Inc.) has grown to become a significant international voice in New Zealand ceramics. The affiliation of about three dozen independent pottery clubs throughout New Zealand together with a number of corporate businesses greatly increases its effective membership. We are a national, not-for-profit organisation representing the interests of practising potters and ceramicists, students of ceramics and all those interested in New Zealand ceramics. We actively support and promote quality, and we encourage and support specialist ceramics education nationally.
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